Laboratory evaluation of a fully automated chemiluminiscence immunoassay for rapid detection of HBsAg, antibodies to HIV and hepatitis C virus.

Background: The Ortho ECi assay employs an immunometric technique with enhanced chemiluminiscence for optimal assay performance. The performance of a fully automated, randomaccess, enhanced chemiluminiscence immunoassay (Ortho ECi) for the detection of HBsAg, anti-HIV and anti-HCV in the serum of blood donors was evaluated at Department of Transfusion Medicine, SPS Apollo Hospitals, Ludhiana, for a period of 14 months (June 2005 to August 2006). Aims: To evaluate the working of Ortho ECi for routine screening of blood donors. Materials and Methods: 2341 samples were processed on Ortho ECi system for all three parameters. The reactive samples were re-run on the same system. Repeat reactive samples were then sent for confirmation at the Ortho Diagnostic.s reference laboratory. Results: The overall concordance between the Ortho ECi assays for HBsAg, anti HIV and anti HCV and the corresponding confiiniatory tests was 100%, 99.8% and 99.8% respectively. The specificities of the assays for HBsAg, anti HIV and anti HCV were 100%, 99.9% and 99.8% respectively. The sensitivities of the assays for HBsAg, anti HIV and anti HCV were 100%, 100% and 100% respectively. The Positive Predictive values (PPV) of the assays for HBsAg, anti HIV and anti HCV were 100%, 33% and 85% respectively. The Negative Predictive values (NPV) of the assays for HBsAg, anti HIV and anti HCV were 100%, 100% and 100% respectively. Conclusions: The Ortho ECi assays for diagnosis of HBsAg, anti- HIV and anti-HCV are highly specific and sensitive assays. The rapid turn around time (TAT), random access, full automation and high throughput make it an effective assay system for blood bank screening programmes for blood donors, thus increasing the patient safety. The instrument has an additional advantages of intellicheck feature, closed system, capability of processing STAT samples and being user friendly with touch-screen. [ABSTRACT FROM AUTHOR]